Friend is annoying me?

[Simone]

My friend who is also my cousin keeps copying off me. We are in the same Game Art class and sometimes we write essays and she tries to take my paper and copy it. I said,"really?" and she laughed. I made an excuse and said that I'm not done and I need to revise it. Then when I was done, I gave it to the teacher without letting her copy.

When the teaher is explaining something on the computer, she will be on facebook the entire time and when we have to start our assignment, she will keep asking me what to do. I can't even do what I have to do since she wants me to show her every step even though the teacher just explained. I will say," Wait a second, let me do some of my work and then I will help." But she will keep bothering me until I help. I don't mind helping but she doesn't make an effort. She makes an effort to go on social network websites.

When we have to go get papers off the teachers desk, she will ask me to get her some too. I got my own and she was like, hey what about mine. So she went up and got it herself.

I am quiet and nice. In the past I let people take advantage of me in this way, but now I don't let it happen. By the way, she has been doing this since the beginning of school. That's why I'm starting to not allow her to use me like this.

What should I do? What's the best way to tell her to stop doing these annoying habits?